diff --git a/flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/DemoFrame.java b/flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/DemoFrame.java
index cb81ce41..10930e52 100644
--- a/flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/DemoFrame.java
+++ b/flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/DemoFrame.java
@@ -141,11 +141,16 @@ class DemoFrame
 	private void windowDecorationsChanged() {
 		boolean windowDecorations = windowDecorationsCheckBoxMenuItem.isSelected();
 
+		// change window decoration of demo main frame
 		dispose();
 		setUndecorated( windowDecorations );
 		getRootPane().setWindowDecorationStyle( windowDecorations ? JRootPane.FRAME : JRootPane.NONE );
 		menuBarEmbeddedCheckBoxMenuItem.setEnabled( windowDecorations );
 		setVisible( true );
+
+		// enable/disable window decoration for later created frames/dialogs
+		JFrame.setDefaultLookAndFeelDecorated( windowDecorations );
+		JDialog.setDefaultLookAndFeelDecorated( windowDecorations );
 	}
 
 	private void menuBarEmbeddedChanged() {